Lesson Overview Students will study sea-floor spreading, a mechanism for plate movement. The students will discover why the Atlantic Ocean is expanding by making observations of the features of the ocean floor. Students will use evidence to explain the theory and make a model that simulates the actual events that occur on the sea floor.
Objectives
Students will analyze and synthesize the evidence provided in the activity to develop a theory to explain why the Atlantic Ocean is expanding.
Students will construct models to demonstrate sea-floor spreading.
Students will develop inquiry skills by analyzing, summarizing, and discussing evidence.
Materials Paper Markers Rulers Worksheets for the lab (3) Homework worksheet
Opening Question of the day: Is the Atlantic Ocean growing? As the students are walking in get them to sit with their lab partners. Also write that they are to sit with their lab partners on the board. Open with the video. (5 min)
Learning Activities Show only about 2 minutes or so of the video. Then abruptly turn it off. You receive an email from a scientist at the United States Geological survey, and he needs your help. Imagine that you are on board the deep-sea exploring vehicle Alvin. Today we are going to work as scientists. Pass out the handout with the email on it, and the questions to the students. Students will work in groups on this task. When they have completed that task they will then create the model of sea floor spreading. And answer a few more questions. Total time of about (40 minutes)
Closing The teacher conducts a discussion. Based on what you learned during the activity, what’s a good definition for sea floor spreading? Where is this new crust formed? How is new crust formed? What happens to the old crust that was originally near the mid-ocean ridge? What do you think is causing the old crust to move towards the deep-ocean trench? If the ocean floor did not spread apart or move, what would you expect to happen near the mid-ocean ridge as the magma is coming from the mantle? What is some evidence near the mid-ocean ridge that helped you determine that the ocean floor was expanding and spreading apart? What can you tell me about the ages of the rock? What can you tell me about the polarity of the rocks around the mid-ocean ridge? What effect do you think sea-floor spreading has on the size of the ocean floor? Where does all of this crust go? Does the ocean keep getting bigger? What is this process called? What is it? What do you think happens when the crust enters the deep-ocean trench? What effect do you think subduction has on the size of the ocean floor? We know that the Atlantic Ocean is continuously expanding. What’s stopping it from expanding and taking over the entire world? (10 min)
Assessment
Homework Depending on how quickly the groups finish the activity, they will finish the lab for homework and answer a few questions on sea floor spreading for homework.
Unit: Plate Tectonics
Title: Sea Floor Spreading Lab
Lesson Overview
Students will study sea-floor spreading, a mechanism for plate movement. The students will discover why the Atlantic Ocean is expanding by making observations of the features of the ocean floor. Students will use evidence to explain the theory and make a model that simulates the actual events that occur on the sea floor.
Objectives
Materials
Paper
Markers
Rulers
Worksheets for the lab (3)
Homework worksheet
Links to Resources
**http://www.youtube.com/watch?v=m8oo_t_09Qs** Short video about mid ocean ridges
Safety Issues
Instruction
Opening
Question of the day: Is the Atlantic Ocean growing? As the students are walking in get them to sit with their lab partners. Also write that they are to sit with their lab partners on the board. Open with the video.
(5 min)
Learning Activities
Show only about 2 minutes or so of the video. Then abruptly turn it off. You receive an email from a scientist at the United States Geological survey, and he needs your help. Imagine that you are on board the deep-sea exploring vehicle Alvin. Today we are going to work as scientists. Pass out the handout with the email on it, and the questions to the students. Students will work in groups on this task. When they have completed that task they will then create the model of sea floor spreading. And answer a few more questions.
Total time of about (40 minutes)
Closing
The teacher conducts a discussion. Based on what you learned during the activity, what’s a good definition for sea floor spreading? Where is this new crust formed? How is new crust formed? What happens to the old crust that was originally near the mid-ocean ridge? What do you think is causing the old crust to move towards the deep-ocean trench? If the ocean floor did not spread apart or move, what would you expect to happen near the mid-ocean ridge as the magma is coming from the mantle? What is some evidence near the mid-ocean ridge that helped you determine that the ocean floor was expanding and spreading apart? What can you tell me about the ages of the rock? What can you tell me about the polarity of the rocks around the mid-ocean ridge? What effect do you think sea-floor spreading has on the size of the ocean floor? Where does all of this crust go? Does the ocean keep getting bigger? What is this process called? What is it? What do you think happens when the crust enters the deep-ocean trench? What effect do you think subduction has on the size of the ocean floor? We know that the Atlantic Ocean is continuously expanding. What’s stopping it from expanding and taking over the entire world?
(10 min)
Assessment
Homework
Depending on how quickly the groups finish the activity, they will finish the lab for homework and answer a few questions on sea floor spreading for homework.
Additional Notes
Lab modified from http://www.nslc.ucla.edu/STEP/GK12/lessons.htm#Earth_Science_